A touch panel is a device for interactively inputting information to an information processing device such as a computer by touching (pressing) with a finger, pen, or the like.
Touch panels are divided into various types according to the operation principles, such as a resistive type, capacitive type, infrared type, ultrasonic type, and electromagnetic induction type. The resistive type and capacitive type touch panels can be mounted on display devices and the like at low cost. These types of touch panels have therefore been widely used in recent years.
The capacitive type touch panel includes a transparent touch electrode provided on the whole substrate surface, a conductive frame portion provided in the periphery of the touch electrode, a plurality of position detection electrodes connected to the frame portion, and wiring portions connecting each position detection electrode and a position detection circuit for detecting a touched position. The capacitive type touch panel is mounted on, for example, the front surface of a display screen of a liquid crystal display panel.
In the capacitive type touch panel, when the front surface of the display screen, that is, the surface of a substrate that forms the touch panel, is touched, the touch electrode is grounded at the touched point through capacitance of a human body. This causes change in resistance value between each position detection electrode and the grounded point. The position detection circuit detects the touched position based on the change in resistance value between each position detection electrode and the grounded point.
For example, Patent document 1 describes a manufacturing method of a capacitive type touch screen panel (touch panel) that eliminates non-uniform color display in a panel end portion.
Patent document 1: Japanese PCT National Phase Laid-Open Patent Publication No. 2004-537107